1. Field of the Invention
This invention relates to a deflection yoke device provided with a correction circuit in which horizontal and vertical misconvergences appearing on a screen of a color cathode-ray tube are corrected.
2. Description of the Prior Art
With a recent tendency to increase the resolution and size of the screen of a cathode-ray tube (to be referred to as a TV screen hereinafter) in a color TV receiver or in a color display unit, beam driving is performed by a wide-angle deflection scheme. For this reason, in order to improve focusing characteristics, both the field distributions of horizontal and vertical deflection coils tend to linear field distributions. However, if field distributions become more linear, the following misconvergence tends to appear: misconvergence X.sub.H that blue and red beams B and R ar horizontally shifted from each other on the X axis of a TV screen, as shown in FIGS. 1A and 1B; misconvergence Y.sub.H that the blue and red beams B and R are horizontally shifted from each other on the Y axis of the TV screen, as shown in FIGS. 2A and 2B; misconvergence HCR that a green beam G is horizontally shifted from the blue and red beams B and R on the X axis of the TV screen, as shown in FIGS. 3A and 3B; and misconvergence VCR that the green beam G is vertically shifted from the blue and red beams B and R on the Y axis of the TV screen, as shown in FIGS. 4A and 4B.
In order to solve such a problem, in a conventional technique, X.sub.H, Y.sub.H, HCR, and VCR convergence yokes for correcting the misconvergence are arranged on the neck side of a deflection yoke, independently of the deflection yoke, so that the respective misconvergence correcting operations are performed by correction currents respectively supplied from power sources independent of a power source for the deflection yoke to correction coils arranged on the corresponding convergence yokes.
In the above convergence yoke arrangement in which the correction coils are provided for the respective misconvergence correcting operations, however, a plurality of power sources for respectively supplying correction currents to the convergence yokes are required independently of the power source for the deflection yoke, resulting in a complicate arrangement and an increase in cost.